Injured Nick Kyrgios and Alex de Minaur were, on Friday, ruled out of Australia's Davis Cup qualifier against Brazil, dealing captain Lleyton Hewitt a blow in his bid to steer them to the Madrid finals.

The mercurial Kyrgios is dealing with a wrist injury that forced him to retire to jeers from his opening round match in Acapulco this week -- his first since the Australian Open in January.

De Minaur continues to struggle with an abdominal tear that he picked up at the season-opening ATP Cup.

Despite both players being named in the team this week, they will no longer play, with Alex Bolt and doubles specialist John Peers called up instead.

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“When we announced the team earlier in the week, we were hopeful they both would be healthy to play,” said Hewitt.

“As seen in Acapulco during the week, Alex's abdominal injury has flared up and Nick has a wrist complaint, and they need to rest and focus on their recovery.”

John Millman, Jordan Thompson and James Duckworth round out the team to face Brazil in Adelaide from March 6-7.

The winner will join 11 other qualifiers and the 2019 semi-finalists -- Canada, Britain, Russia and Spain -- along with wildcards France and Serbia in the finals in Spain in November.

Australia has met Brazil three times before in the Davis Cup and won on every occasion.